]>
Commit | Line | Data |
---|---|---|
7f2935c7 | 1 | /* Parse C expressions for CCCP. |
a3aa3d8c | 2 | Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998 Free Software Foundation. |
7f2935c7 PB |
3 | |
4 | This program is free software; you can redistribute it and/or modify it | |
5 | under the terms of the GNU General Public License as published by the | |
6 | Free Software Foundation; either version 2, or (at your option) any | |
7 | later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program; if not, write to the Free Software | |
940d9d63 RK |
16 | Foundation, 59 Temple Place - Suite 330, |
17 | Boston, MA 02111-1307, USA. | |
7f2935c7 PB |
18 | |
19 | In other words, you are welcome to use, share and improve this program. | |
20 | You are forbidden to forbid anyone else to use, share and improve | |
21 | what you give them. Help stamp out software-hoarding! | |
22 | ||
0f41302f | 23 | Written by Per Bothner 1994. */ |
7f2935c7 PB |
24 | |
25 | /* Parse a C expression from text in a string */ | |
26 | ||
27 | #include "config.h" | |
b04cd507 | 28 | #include "system.h" |
487a6e06 | 29 | #include "cpplib.h" |
7f2935c7 | 30 | |
9870475c | 31 | #ifdef MULTIBYTE_CHARS |
7f2935c7 PB |
32 | #include <locale.h> |
33 | #endif | |
34 | ||
7f2935c7 PB |
35 | #ifndef CHAR_TYPE_SIZE |
36 | #define CHAR_TYPE_SIZE BITS_PER_UNIT | |
37 | #endif | |
38 | ||
39 | #ifndef INT_TYPE_SIZE | |
40 | #define INT_TYPE_SIZE BITS_PER_WORD | |
41 | #endif | |
42 | ||
43 | #ifndef LONG_TYPE_SIZE | |
44 | #define LONG_TYPE_SIZE BITS_PER_WORD | |
45 | #endif | |
46 | ||
47 | #ifndef WCHAR_TYPE_SIZE | |
48 | #define WCHAR_TYPE_SIZE INT_TYPE_SIZE | |
49 | #endif | |
50 | ||
51 | #ifndef MAX_CHAR_TYPE_SIZE | |
52 | #define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE | |
53 | #endif | |
54 | ||
55 | #ifndef MAX_INT_TYPE_SIZE | |
56 | #define MAX_INT_TYPE_SIZE INT_TYPE_SIZE | |
57 | #endif | |
58 | ||
59 | #ifndef MAX_LONG_TYPE_SIZE | |
60 | #define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE | |
61 | #endif | |
62 | ||
63 | #ifndef MAX_WCHAR_TYPE_SIZE | |
64 | #define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE | |
65 | #endif | |
66 | ||
f1a86df6 ZW |
67 | #define MAX_CHAR_TYPE_MASK (MAX_CHAR_TYPE_SIZE < HOST_BITS_PER_WIDE_INT \ |
68 | ? (~ (~ (HOST_WIDE_INT) 0 << MAX_CHAR_TYPE_SIZE)) \ | |
69 | : ~ (HOST_WIDE_INT) 0) | |
70 | ||
71 | #define MAX_WCHAR_TYPE_MASK (MAX_WCHAR_TYPE_SIZE < HOST_BITS_PER_WIDE_INT \ | |
72 | ? ~ (~ (HOST_WIDE_INT) 0 << MAX_WCHAR_TYPE_SIZE) \ | |
73 | : ~ (HOST_WIDE_INT) 0) | |
74 | ||
7f2935c7 PB |
75 | /* Yield nonzero if adding two numbers with A's and B's signs can yield a |
76 | number with SUM's sign, where A, B, and SUM are all C integers. */ | |
77 | #define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0) | |
78 | ||
b04cd507 KG |
79 | static void integer_overflow PARAMS ((cpp_reader *)); |
80 | static long left_shift PARAMS ((cpp_reader *, long, int, unsigned long)); | |
81 | static long right_shift PARAMS ((cpp_reader *, long, int, unsigned long)); | |
7f2935c7 PB |
82 | |
83 | #define ERROR 299 | |
84 | #define OROR 300 | |
85 | #define ANDAND 301 | |
86 | #define EQUAL 302 | |
87 | #define NOTEQUAL 303 | |
88 | #define LEQ 304 | |
89 | #define GEQ 305 | |
90 | #define LSH 306 | |
91 | #define RSH 307 | |
92 | #define NAME 308 | |
93 | #define INT 309 | |
94 | #define CHAR 310 | |
95 | ||
96 | #define LEFT_OPERAND_REQUIRED 1 | |
97 | #define RIGHT_OPERAND_REQUIRED 2 | |
98 | #define HAVE_VALUE 4 | |
a4a315ef | 99 | /* SKIP_OPERAND is set for '&&' '||' '?' and ':' when the |
0f41302f | 100 | following operand should be short-circuited instead of evaluated. */ |
a4a315ef PB |
101 | #define SKIP_OPERAND 8 |
102 | /*#define UNSIGNEDP 16*/ | |
7f2935c7 | 103 | |
1d300e19 KG |
104 | #ifndef CHAR_BIT |
105 | #define CHAR_BIT 8 | |
7e127823 PB |
106 | #endif |
107 | ||
1d300e19 KG |
108 | #ifndef HOST_BITS_PER_WIDE_INT |
109 | #define HOST_BITS_PER_WIDE_INT (CHAR_BIT * sizeof (HOST_WIDE_INT)) | |
7e127823 PB |
110 | #endif |
111 | ||
7f2935c7 PB |
112 | struct operation { |
113 | short op; | |
0f41302f | 114 | char rprio; /* Priority of op (relative to it right operand). */ |
7f2935c7 PB |
115 | char flags; |
116 | char unsignedp; /* true if value should be treated as unsigned */ | |
0f41302f | 117 | HOST_WIDE_INT value; /* The value logically "right" of op. */ |
7f2935c7 | 118 | }; |
7f2935c7 | 119 | |
f13eb63a ZW |
120 | /* Parse and convert an integer for #if. Accepts decimal, hex, or octal |
121 | with or without size suffixes. */ | |
7f2935c7 | 122 | |
f13eb63a ZW |
123 | static struct operation |
124 | parse_number (pfile, start, end) | |
7f2935c7 | 125 | cpp_reader *pfile; |
f13eb63a ZW |
126 | U_CHAR *start; |
127 | U_CHAR *end; | |
7f2935c7 PB |
128 | { |
129 | struct operation op; | |
f13eb63a ZW |
130 | U_CHAR *p = start; |
131 | int c; | |
132 | unsigned HOST_WIDE_INT n = 0, nd, MAX_over_base; | |
133 | int base = 10; | |
134 | int overflow = 0; | |
135 | int digit, largest_digit = 0; | |
7f2935c7 PB |
136 | int spec_long = 0; |
137 | ||
138 | op.unsignedp = 0; | |
139 | ||
f13eb63a ZW |
140 | if (p[0] == '0') |
141 | { | |
142 | if (end - start >= 3 && (p[1] == 'x' || p[1] == 'X')) | |
143 | { | |
144 | p += 2; | |
145 | base = 16; | |
146 | } | |
147 | else | |
148 | { | |
149 | p += 1; | |
150 | base = 8; | |
151 | } | |
7f2935c7 PB |
152 | } |
153 | ||
0f41302f | 154 | /* Some buggy compilers (e.g. MPW C) seem to need both casts. */ |
f13eb63a ZW |
155 | MAX_over_base = (((unsigned HOST_WIDE_INT) -1) |
156 | / ((unsigned HOST_WIDE_INT) base)); | |
7f2935c7 | 157 | |
f13eb63a ZW |
158 | while (p < end) |
159 | { | |
160 | c = *p++; | |
161 | ||
162 | if (c >= '0' && c <= '9') | |
163 | digit = c - '0'; | |
164 | else if (base == 16 && c >= 'a' && c <= 'f') /* FIXME: assumes ASCII */ | |
165 | digit = c - 'a' + 10; | |
166 | else if (base == 16 && c >= 'A' && c <= 'F') | |
167 | digit = c - 'A' + 10; | |
168 | else if (c == '.') | |
169 | { | |
170 | /* It's a float since it contains a point. */ | |
171 | cpp_error (pfile, | |
172 | "floating point numbers are not allowed in #if expressions"); | |
173 | goto error; | |
174 | } | |
175 | else | |
176 | { | |
177 | /* `l' means long, and `u' means unsigned. */ | |
178 | for (;;) | |
179 | { | |
180 | if (c == 'l' || c == 'L') | |
181 | spec_long++; | |
182 | else if (c == 'u' || c == 'U') | |
183 | op.unsignedp++; | |
184 | else | |
185 | { | |
186 | /* Decrement p here so that the error for an invalid number | |
187 | will be generated below in the case where this is the | |
188 | last character in the buffer. */ | |
189 | p--; | |
190 | break; | |
191 | } | |
192 | if (p == end) | |
193 | break; | |
194 | c = *p++; | |
195 | } | |
196 | /* Don't look for any more digits after the suffixes. */ | |
7f2935c7 | 197 | break; |
f13eb63a ZW |
198 | } |
199 | ||
200 | if (largest_digit < digit) | |
201 | largest_digit = digit; | |
202 | nd = n * base + digit; | |
203 | overflow |= MAX_over_base < n || nd < n; | |
204 | n = nd; | |
7f2935c7 | 205 | } |
7f2935c7 | 206 | |
f13eb63a | 207 | if (p != end) |
7f2935c7 | 208 | { |
f13eb63a ZW |
209 | cpp_error (pfile, "invalid number in #if expression"); |
210 | goto error; | |
7f2935c7 | 211 | } |
f13eb63a ZW |
212 | else if (spec_long > (CPP_OPTIONS (pfile)->c89 ? 1 : 2)) |
213 | { | |
214 | cpp_error (pfile, "too many `l' suffixes in integer constant"); | |
215 | goto error; | |
216 | } | |
217 | else if (op.unsignedp > 1) | |
218 | { | |
219 | cpp_error (pfile, "too many `u' suffixes in integer constant"); | |
220 | goto error; | |
221 | } | |
222 | ||
7f2935c7 | 223 | if (base <= largest_digit) |
7c4033ff | 224 | cpp_pedwarn (pfile, "integer constant contains digits beyond the radix"); |
7f2935c7 PB |
225 | |
226 | if (overflow) | |
7c4033ff | 227 | cpp_pedwarn (pfile, "integer constant out of range"); |
7f2935c7 PB |
228 | |
229 | /* If too big to be signed, consider it unsigned. */ | |
f13eb63a | 230 | else if ((HOST_WIDE_INT) n < 0 && ! op.unsignedp) |
7f2935c7 PB |
231 | { |
232 | if (base == 10) | |
f13eb63a ZW |
233 | cpp_warning (pfile, |
234 | "integer constant is so large that it is unsigned"); | |
7f2935c7 PB |
235 | op.unsignedp = 1; |
236 | } | |
237 | ||
238 | op.value = n; | |
239 | op.op = INT; | |
240 | return op; | |
f13eb63a ZW |
241 | |
242 | error: | |
243 | op.op = ERROR; | |
244 | return op; | |
7f2935c7 PB |
245 | } |
246 | ||
f13eb63a ZW |
247 | /* Parse and convert a character constant for #if. Understands backslash |
248 | escapes (\n, \031) and multibyte characters (if so configured). */ | |
249 | static struct operation | |
250 | parse_charconst (pfile, start, end) | |
251 | cpp_reader *pfile; | |
252 | U_CHAR *start; | |
253 | U_CHAR *end; | |
254 | { | |
255 | struct operation op; | |
256 | HOST_WIDE_INT result = 0; | |
257 | int num_chars = 0; | |
258 | int num_bits; | |
259 | unsigned int width = MAX_CHAR_TYPE_SIZE, mask = MAX_CHAR_TYPE_MASK; | |
260 | int max_chars; | |
261 | U_CHAR *ptr = start; | |
262 | ||
263 | /* FIXME: Should use reentrant multibyte functions. */ | |
264 | #ifdef MULTIBYTE_CHARS | |
265 | wchar_t c; | |
266 | (void) mbtowc (NULL_PTR, NULL_PTR, 0); | |
267 | #else | |
268 | int c; | |
269 | #endif | |
270 | ||
271 | if (*ptr == 'L') | |
272 | { | |
273 | ++ptr; | |
274 | width = MAX_WCHAR_TYPE_SIZE, mask = MAX_WCHAR_TYPE_MASK; | |
275 | } | |
276 | max_chars = MAX_LONG_TYPE_SIZE / width; | |
277 | ||
278 | ++ptr; /* skip initial quote */ | |
279 | ||
280 | while (ptr < end) | |
281 | { | |
282 | #ifndef MULTIBYTE_CHARS | |
283 | c = *ptr++; | |
284 | #else | |
285 | ptr += mbtowc (&c, ptr, end - ptr); | |
286 | #endif | |
287 | if (c == '\'' || c == '\0') | |
288 | break; | |
289 | else if (c == '\\') | |
290 | { | |
291 | /* Hopefully valid assumption: if mbtowc returns a backslash, | |
292 | we are in initial shift state. No valid escape-sequence | |
293 | character can take us out of initial shift state or begin | |
294 | an unshifted multibyte char, so cpp_parse_escape doesn't | |
295 | need to know about multibyte chars. */ | |
296 | ||
297 | c = cpp_parse_escape (pfile, (char **) &ptr, mask); | |
298 | if (width < HOST_BITS_PER_INT | |
299 | && (unsigned int) c >= (unsigned int)(1 << width)) | |
300 | cpp_pedwarn (pfile, "escape sequence out of range for character"); | |
301 | } | |
302 | ||
303 | /* Merge character into result; ignore excess chars. */ | |
304 | if (++num_chars <= max_chars) | |
305 | { | |
306 | if (width < HOST_BITS_PER_INT) | |
307 | result = (result << width) | (c & ((1 << width) - 1)); | |
308 | else | |
309 | result = c; | |
310 | } | |
311 | } | |
312 | ||
313 | if (num_chars == 0) | |
314 | { | |
315 | cpp_error (pfile, "empty character constant"); | |
316 | goto error; | |
317 | } | |
318 | else if (c != '\'') | |
319 | { | |
320 | /* cpp_get_token has already emitted an error if !traditional. */ | |
321 | if (! CPP_TRADITIONAL (pfile)) | |
322 | cpp_error (pfile, "malformatted character constant"); | |
323 | goto error; | |
324 | } | |
325 | else if (num_chars > max_chars) | |
326 | { | |
327 | cpp_error (pfile, "character constant too long"); | |
328 | goto error; | |
329 | } | |
330 | else if (num_chars != 1 && ! CPP_TRADITIONAL (pfile)) | |
331 | cpp_warning (pfile, "multi-character character constant"); | |
332 | ||
333 | /* If char type is signed, sign-extend the constant. */ | |
334 | num_bits = num_chars * width; | |
335 | ||
336 | if (cpp_lookup (pfile, (U_CHAR *)"__CHAR_UNSIGNED__", | |
337 | sizeof ("__CHAR_UNSIGNED__")-1, -1) | |
338 | || ((result >> (num_bits - 1)) & 1) == 0) | |
339 | op.value = result & ((unsigned long) ~0 | |
340 | >> (HOST_BITS_PER_LONG - num_bits)); | |
341 | else | |
342 | op.value = result | ~((unsigned long) ~0 | |
343 | >> (HOST_BITS_PER_LONG - num_bits)); | |
344 | ||
345 | /* This is always a signed type. */ | |
346 | op.unsignedp = 0; | |
347 | op.op = CHAR; | |
348 | return op; | |
349 | ||
350 | error: | |
351 | op.op = ERROR; | |
352 | return op; | |
353 | } | |
354 | ||
355 | ||
7f2935c7 PB |
356 | struct token { |
357 | char *operator; | |
358 | int token; | |
359 | }; | |
360 | ||
361 | static struct token tokentab2[] = { | |
362 | {"&&", ANDAND}, | |
363 | {"||", OROR}, | |
364 | {"<<", LSH}, | |
365 | {">>", RSH}, | |
366 | {"==", EQUAL}, | |
367 | {"!=", NOTEQUAL}, | |
368 | {"<=", LEQ}, | |
369 | {">=", GEQ}, | |
370 | {"++", ERROR}, | |
371 | {"--", ERROR}, | |
372 | {NULL, ERROR} | |
373 | }; | |
374 | ||
0f41302f | 375 | /* Read one token. */ |
7f2935c7 PB |
376 | |
377 | struct operation | |
c9666c01 | 378 | cpp_lex (pfile, skip_evaluation) |
52529158 | 379 | cpp_reader *pfile; |
c9666c01 | 380 | int skip_evaluation; |
7f2935c7 | 381 | { |
f13eb63a ZW |
382 | U_CHAR c; |
383 | struct token *toktab; | |
7f2935c7 PB |
384 | enum cpp_token token; |
385 | struct operation op; | |
386 | U_CHAR *tok_start, *tok_end; | |
387 | int old_written; | |
388 | ||
389 | retry: | |
390 | ||
1519594d PB |
391 | old_written = CPP_WRITTEN (pfile); |
392 | cpp_skip_hspace (pfile); | |
7f2935c7 PB |
393 | c = CPP_BUF_PEEK (CPP_BUFFER (pfile)); |
394 | if (c == '#') | |
7061aa5a ZW |
395 | { |
396 | op.op = INT; | |
397 | op.value = cpp_read_check_assertion (pfile); | |
398 | return op; | |
399 | } | |
7f2935c7 | 400 | |
7f2935c7 PB |
401 | if (c == '\n') |
402 | { | |
403 | op.op = 0; | |
404 | return op; | |
405 | } | |
406 | ||
407 | token = cpp_get_token (pfile); | |
408 | tok_start = pfile->token_buffer + old_written; | |
409 | tok_end = CPP_PWRITTEN (pfile); | |
410 | pfile->limit = tok_start; | |
411 | switch (token) | |
412 | { | |
0f41302f | 413 | case CPP_EOF: /* Should not happen ... */ |
a4a315ef | 414 | case CPP_VSPACE: |
7f2935c7 PB |
415 | op.op = 0; |
416 | return op; | |
7f2935c7 PB |
417 | case CPP_POP: |
418 | if (CPP_BUFFER (pfile)->fname != NULL) | |
419 | { | |
420 | op.op = 0; | |
421 | return op; | |
422 | } | |
a4a315ef | 423 | cpp_pop_buffer (pfile); |
7f2935c7 | 424 | goto retry; |
f13eb63a ZW |
425 | case CPP_HSPACE: |
426 | case CPP_COMMENT: | |
7f2935c7 PB |
427 | goto retry; |
428 | case CPP_NUMBER: | |
f13eb63a | 429 | return parse_number (pfile, tok_start, tok_end); |
7f2935c7 PB |
430 | case CPP_STRING: |
431 | cpp_error (pfile, "string constants not allowed in #if expressions"); | |
432 | op.op = ERROR; | |
433 | return op; | |
434 | case CPP_CHAR: | |
f13eb63a | 435 | return parse_charconst (pfile, tok_start, tok_end); |
7f2935c7 PB |
436 | |
437 | case CPP_NAME: | |
c9666c01 RK |
438 | if (CPP_WARN_UNDEF (pfile) && !skip_evaluation) |
439 | cpp_warning (pfile, "`%.*s' is not defined", | |
440 | (int) (tok_end - tok_start), tok_start); | |
f13eb63a ZW |
441 | op.op = INT; |
442 | op.unsignedp = 0; | |
443 | op.value = 0; | |
444 | return op; | |
7f2935c7 PB |
445 | |
446 | case CPP_OTHER: | |
447 | /* See if it is a special token of length 2. */ | |
448 | if (tok_start + 2 == tok_end) | |
449 | { | |
450 | for (toktab = tokentab2; toktab->operator != NULL; toktab++) | |
451 | if (tok_start[0] == toktab->operator[0] | |
452 | && tok_start[1] == toktab->operator[1]) | |
453 | break; | |
454 | if (toktab->token == ERROR) | |
ab87f8c8 JL |
455 | cpp_error (pfile, "`%s' not allowed in operand of `#if'", |
456 | tok_start); | |
7f2935c7 PB |
457 | op.op = toktab->token; |
458 | return op; | |
459 | } | |
460 | /* fall through */ | |
461 | default: | |
462 | op.op = *tok_start; | |
463 | return op; | |
464 | } | |
465 | } | |
466 | ||
467 | ||
468 | /* Parse a C escape sequence. STRING_PTR points to a variable | |
469 | containing a pointer to the string to parse. That pointer | |
470 | is updated past the characters we use. The value of the | |
471 | escape sequence is returned. | |
472 | ||
473 | A negative value means the sequence \ newline was seen, | |
474 | which is supposed to be equivalent to nothing at all. | |
475 | ||
476 | If \ is followed by a null character, we return a negative | |
477 | value and leave the string pointer pointing at the null character. | |
478 | ||
479 | If \ is followed by 000, we return 0 and leave the string pointer | |
480 | after the zeros. A value of 0 does not mean end of string. */ | |
481 | ||
f1a86df6 ZW |
482 | HOST_WIDE_INT |
483 | cpp_parse_escape (pfile, string_ptr, result_mask) | |
7f2935c7 PB |
484 | cpp_reader *pfile; |
485 | char **string_ptr; | |
f1a86df6 | 486 | HOST_WIDE_INT result_mask; |
7f2935c7 PB |
487 | { |
488 | register int c = *(*string_ptr)++; | |
489 | switch (c) | |
490 | { | |
491 | case 'a': | |
492 | return TARGET_BELL; | |
493 | case 'b': | |
494 | return TARGET_BS; | |
495 | case 'e': | |
496 | case 'E': | |
f1a86df6 | 497 | if (CPP_OPTIONS (pfile)->pedantic) |
7f2935c7 PB |
498 | cpp_pedwarn (pfile, "non-ANSI-standard escape sequence, `\\%c'", c); |
499 | return 033; | |
500 | case 'f': | |
501 | return TARGET_FF; | |
502 | case 'n': | |
503 | return TARGET_NEWLINE; | |
504 | case 'r': | |
505 | return TARGET_CR; | |
506 | case 't': | |
507 | return TARGET_TAB; | |
508 | case 'v': | |
509 | return TARGET_VT; | |
510 | case '\n': | |
511 | return -2; | |
512 | case 0: | |
513 | (*string_ptr)--; | |
514 | return 0; | |
515 | ||
516 | case '0': | |
517 | case '1': | |
518 | case '2': | |
519 | case '3': | |
520 | case '4': | |
521 | case '5': | |
522 | case '6': | |
523 | case '7': | |
524 | { | |
f1a86df6 | 525 | register HOST_WIDE_INT i = c - '0'; |
7f2935c7 PB |
526 | register int count = 0; |
527 | while (++count < 3) | |
528 | { | |
529 | c = *(*string_ptr)++; | |
530 | if (c >= '0' && c <= '7') | |
531 | i = (i << 3) + c - '0'; | |
532 | else | |
533 | { | |
534 | (*string_ptr)--; | |
535 | break; | |
536 | } | |
537 | } | |
f1a86df6 | 538 | if (i != (i & result_mask)) |
7f2935c7 | 539 | { |
f1a86df6 ZW |
540 | i &= result_mask; |
541 | cpp_pedwarn (pfile, "octal escape sequence out of range"); | |
7f2935c7 PB |
542 | } |
543 | return i; | |
544 | } | |
545 | case 'x': | |
546 | { | |
f1a86df6 ZW |
547 | register unsigned HOST_WIDE_INT i = 0, overflow = 0; |
548 | register int digits_found = 0, digit; | |
7f2935c7 PB |
549 | for (;;) |
550 | { | |
551 | c = *(*string_ptr)++; | |
552 | if (c >= '0' && c <= '9') | |
553 | digit = c - '0'; | |
554 | else if (c >= 'a' && c <= 'f') | |
555 | digit = c - 'a' + 10; | |
556 | else if (c >= 'A' && c <= 'F') | |
557 | digit = c - 'A' + 10; | |
558 | else | |
559 | { | |
560 | (*string_ptr)--; | |
561 | break; | |
562 | } | |
563 | overflow |= i ^ (i << 4 >> 4); | |
564 | i = (i << 4) + digit; | |
565 | digits_found = 1; | |
566 | } | |
567 | if (!digits_found) | |
568 | cpp_error (pfile, "\\x used with no following hex digits"); | |
f1a86df6 | 569 | if (overflow | (i != (i & result_mask))) |
7f2935c7 | 570 | { |
f1a86df6 ZW |
571 | i &= result_mask; |
572 | cpp_pedwarn (pfile, "hex escape sequence out of range"); | |
7f2935c7 PB |
573 | } |
574 | return i; | |
575 | } | |
576 | default: | |
577 | return c; | |
578 | } | |
579 | } | |
580 | ||
581 | static void | |
582 | integer_overflow (pfile) | |
583 | cpp_reader *pfile; | |
584 | { | |
585 | if (CPP_PEDANTIC (pfile)) | |
586 | cpp_pedwarn (pfile, "integer overflow in preprocessor expression"); | |
587 | } | |
588 | ||
589 | static long | |
590 | left_shift (pfile, a, unsignedp, b) | |
591 | cpp_reader *pfile; | |
592 | long a; | |
593 | int unsignedp; | |
594 | unsigned long b; | |
595 | { | |
596 | if (b >= HOST_BITS_PER_LONG) | |
597 | { | |
598 | if (! unsignedp && a != 0) | |
599 | integer_overflow (pfile); | |
600 | return 0; | |
601 | } | |
602 | else if (unsignedp) | |
603 | return (unsigned long) a << b; | |
604 | else | |
605 | { | |
606 | long l = a << b; | |
607 | if (l >> b != a) | |
608 | integer_overflow (pfile); | |
609 | return l; | |
610 | } | |
611 | } | |
612 | ||
613 | static long | |
614 | right_shift (pfile, a, unsignedp, b) | |
d6f4ec51 | 615 | cpp_reader *pfile ATTRIBUTE_UNUSED; |
7f2935c7 PB |
616 | long a; |
617 | int unsignedp; | |
618 | unsigned long b; | |
619 | { | |
620 | if (b >= HOST_BITS_PER_LONG) | |
621 | return unsignedp ? 0 : a >> (HOST_BITS_PER_LONG - 1); | |
622 | else if (unsignedp) | |
623 | return (unsigned long) a >> b; | |
624 | else | |
625 | return a >> b; | |
626 | } | |
627 | \f | |
0f41302f | 628 | /* These priorities are all even, so we can handle associatively. */ |
7f2935c7 PB |
629 | #define PAREN_INNER_PRIO 0 |
630 | #define COMMA_PRIO 4 | |
631 | #define COND_PRIO (COMMA_PRIO+2) | |
632 | #define OROR_PRIO (COND_PRIO+2) | |
633 | #define ANDAND_PRIO (OROR_PRIO+2) | |
634 | #define OR_PRIO (ANDAND_PRIO+2) | |
635 | #define XOR_PRIO (OR_PRIO+2) | |
636 | #define AND_PRIO (XOR_PRIO+2) | |
637 | #define EQUAL_PRIO (AND_PRIO+2) | |
638 | #define LESS_PRIO (EQUAL_PRIO+2) | |
639 | #define SHIFT_PRIO (LESS_PRIO+2) | |
640 | #define PLUS_PRIO (SHIFT_PRIO+2) | |
641 | #define MUL_PRIO (PLUS_PRIO+2) | |
642 | #define UNARY_PRIO (MUL_PRIO+2) | |
643 | #define PAREN_OUTER_PRIO (UNARY_PRIO+2) | |
644 | ||
645 | #define COMPARE(OP) \ | |
646 | top->unsignedp = 0;\ | |
faa76596 ZW |
647 | top->value = (unsigned1 || unsigned2) \ |
648 | ? (unsigned long) v1 OP (unsigned long) v2 : (v1 OP v2) | |
7f2935c7 PB |
649 | |
650 | /* Parse and evaluate a C expression, reading from PFILE. | |
651 | Returns the value of the expression. */ | |
652 | ||
7e127823 | 653 | HOST_WIDE_INT |
7f2935c7 PB |
654 | cpp_parse_expr (pfile) |
655 | cpp_reader *pfile; | |
656 | { | |
657 | /* The implementation is an operator precedence parser, | |
658 | i.e. a bottom-up parser, using a stack for not-yet-reduced tokens. | |
659 | ||
660 | The stack base is 'stack', and the current stack pointer is 'top'. | |
661 | There is a stack element for each operator (only), | |
662 | and the most recently pushed operator is 'top->op'. | |
663 | An operand (value) is stored in the 'value' field of the stack | |
664 | element of the operator that precedes it. | |
665 | In that case the 'flags' field has the HAVE_VALUE flag set. */ | |
666 | ||
667 | #define INIT_STACK_SIZE 20 | |
668 | struct operation init_stack[INIT_STACK_SIZE]; | |
669 | struct operation *stack = init_stack; | |
670 | struct operation *limit = stack + INIT_STACK_SIZE; | |
671 | register struct operation *top = stack; | |
672 | int lprio, rprio; | |
a4a315ef | 673 | int skip_evaluation = 0; |
7f2935c7 PB |
674 | |
675 | top->rprio = 0; | |
676 | top->flags = 0; | |
677 | for (;;) | |
678 | { | |
679 | struct operation op; | |
680 | char flags = 0; | |
681 | ||
682 | /* Read a token */ | |
c9666c01 | 683 | op = cpp_lex (pfile, skip_evaluation); |
7f2935c7 PB |
684 | |
685 | /* See if the token is an operand, in which case go to set_value. | |
686 | If the token is an operator, figure out its left and right | |
0f41302f | 687 | priorities, and then goto maybe_reduce. */ |
7f2935c7 PB |
688 | |
689 | switch (op.op) | |
690 | { | |
691 | case NAME: | |
c9666c01 | 692 | abort (); |
7f2935c7 PB |
693 | case INT: case CHAR: |
694 | top->value = op.value; | |
695 | top->unsignedp = op.unsignedp; | |
696 | goto set_value; | |
697 | case 0: | |
698 | lprio = 0; goto maybe_reduce; | |
699 | case '+': case '-': | |
700 | /* Is this correct if unary ? FIXME */ | |
701 | flags = RIGHT_OPERAND_REQUIRED; | |
702 | lprio = PLUS_PRIO; rprio = lprio + 1; goto maybe_reduce; | |
703 | case '!': case '~': | |
704 | flags = RIGHT_OPERAND_REQUIRED; | |
705 | rprio = UNARY_PRIO; lprio = rprio + 1; goto maybe_reduce; | |
706 | case '*': case '/': case '%': | |
707 | lprio = MUL_PRIO; goto binop; | |
708 | case '<': case '>': case LEQ: case GEQ: | |
709 | lprio = LESS_PRIO; goto binop; | |
710 | case EQUAL: case NOTEQUAL: | |
711 | lprio = EQUAL_PRIO; goto binop; | |
712 | case LSH: case RSH: | |
713 | lprio = SHIFT_PRIO; goto binop; | |
714 | case '&': lprio = AND_PRIO; goto binop; | |
715 | case '^': lprio = XOR_PRIO; goto binop; | |
716 | case '|': lprio = OR_PRIO; goto binop; | |
717 | case ANDAND: lprio = ANDAND_PRIO; goto binop; | |
718 | case OROR: lprio = OROR_PRIO; goto binop; | |
719 | case ',': | |
720 | lprio = COMMA_PRIO; goto binop; | |
721 | case '(': | |
722 | lprio = PAREN_OUTER_PRIO; rprio = PAREN_INNER_PRIO; | |
723 | goto maybe_reduce; | |
724 | case ')': | |
725 | lprio = PAREN_INNER_PRIO; rprio = PAREN_OUTER_PRIO; | |
726 | goto maybe_reduce; | |
727 | case ':': | |
728 | lprio = COND_PRIO; rprio = COND_PRIO; | |
729 | goto maybe_reduce; | |
730 | case '?': | |
731 | lprio = COND_PRIO + 1; rprio = COND_PRIO; | |
732 | goto maybe_reduce; | |
f13eb63a ZW |
733 | case ERROR: |
734 | goto syntax_error; | |
7f2935c7 PB |
735 | binop: |
736 | flags = LEFT_OPERAND_REQUIRED|RIGHT_OPERAND_REQUIRED; | |
737 | rprio = lprio + 1; | |
738 | goto maybe_reduce; | |
739 | default: | |
740 | cpp_error (pfile, "invalid character in #if"); | |
741 | goto syntax_error; | |
742 | } | |
743 | ||
744 | set_value: | |
0f41302f | 745 | /* Push a value onto the stack. */ |
7f2935c7 PB |
746 | if (top->flags & HAVE_VALUE) |
747 | { | |
748 | cpp_error (pfile, "syntax error in #if"); | |
749 | goto syntax_error; | |
750 | } | |
751 | top->flags |= HAVE_VALUE; | |
752 | continue; | |
753 | ||
754 | maybe_reduce: | |
0f41302f | 755 | /* Push an operator, and check if we can reduce now. */ |
7f2935c7 PB |
756 | while (top->rprio > lprio) |
757 | { | |
758 | long v1 = top[-1].value, v2 = top[0].value; | |
759 | int unsigned1 = top[-1].unsignedp, unsigned2 = top[0].unsignedp; | |
760 | top--; | |
761 | if ((top[1].flags & LEFT_OPERAND_REQUIRED) | |
762 | && ! (top[0].flags & HAVE_VALUE)) | |
763 | { | |
764 | cpp_error (pfile, "syntax error - missing left operand"); | |
765 | goto syntax_error; | |
766 | } | |
767 | if ((top[1].flags & RIGHT_OPERAND_REQUIRED) | |
768 | && ! (top[1].flags & HAVE_VALUE)) | |
769 | { | |
770 | cpp_error (pfile, "syntax error - missing right operand"); | |
771 | goto syntax_error; | |
772 | } | |
773 | /* top[0].value = (top[1].op)(v1, v2);*/ | |
774 | switch (top[1].op) | |
775 | { | |
776 | case '+': | |
777 | if (!(top->flags & HAVE_VALUE)) | |
778 | { /* Unary '+' */ | |
779 | top->value = v2; | |
780 | top->unsignedp = unsigned2; | |
781 | top->flags |= HAVE_VALUE; | |
782 | } | |
783 | else | |
784 | { | |
785 | top->value = v1 + v2; | |
786 | top->unsignedp = unsigned1 || unsigned2; | |
a4a315ef | 787 | if (! top->unsignedp && ! skip_evaluation |
7f2935c7 PB |
788 | && ! possible_sum_sign (v1, v2, top->value)) |
789 | integer_overflow (pfile); | |
790 | } | |
791 | break; | |
792 | case '-': | |
52529158 | 793 | if (!(top->flags & HAVE_VALUE)) |
7f2935c7 PB |
794 | { /* Unary '-' */ |
795 | top->value = - v2; | |
52529158 | 796 | if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2) |
7f2935c7 PB |
797 | integer_overflow (pfile); |
798 | top->unsignedp = unsigned2; | |
799 | top->flags |= HAVE_VALUE; | |
800 | } | |
801 | else | |
802 | { /* Binary '-' */ | |
803 | top->value = v1 - v2; | |
804 | top->unsignedp = unsigned1 || unsigned2; | |
52529158 | 805 | if (! top->unsignedp && ! skip_evaluation |
7f2935c7 PB |
806 | && ! possible_sum_sign (top->value, v2, v1)) |
807 | integer_overflow (pfile); | |
808 | } | |
809 | break; | |
810 | case '*': | |
811 | top->unsignedp = unsigned1 || unsigned2; | |
812 | if (top->unsignedp) | |
813 | top->value = (unsigned long) v1 * v2; | |
a4a315ef | 814 | else if (!skip_evaluation) |
7f2935c7 PB |
815 | { |
816 | top->value = v1 * v2; | |
817 | if (v1 | |
818 | && (top->value / v1 != v2 | |
819 | || (top->value & v1 & v2) < 0)) | |
820 | integer_overflow (pfile); | |
821 | } | |
822 | break; | |
823 | case '/': | |
a4a315ef PB |
824 | if (skip_evaluation) |
825 | break; | |
7f2935c7 PB |
826 | if (v2 == 0) |
827 | { | |
828 | cpp_error (pfile, "division by zero in #if"); | |
829 | v2 = 1; | |
830 | } | |
831 | top->unsignedp = unsigned1 || unsigned2; | |
832 | if (top->unsignedp) | |
833 | top->value = (unsigned long) v1 / v2; | |
834 | else | |
835 | { | |
836 | top->value = v1 / v2; | |
837 | if ((top->value & v1 & v2) < 0) | |
838 | integer_overflow (pfile); | |
839 | } | |
840 | break; | |
841 | case '%': | |
a4a315ef PB |
842 | if (skip_evaluation) |
843 | break; | |
7f2935c7 PB |
844 | if (v2 == 0) |
845 | { | |
846 | cpp_error (pfile, "division by zero in #if"); | |
847 | v2 = 1; | |
848 | } | |
849 | top->unsignedp = unsigned1 || unsigned2; | |
850 | if (top->unsignedp) | |
851 | top->value = (unsigned long) v1 % v2; | |
852 | else | |
853 | top->value = v1 % v2; | |
854 | break; | |
855 | case '!': | |
856 | if (top->flags & HAVE_VALUE) | |
857 | { | |
858 | cpp_error (pfile, "syntax error"); | |
859 | goto syntax_error; | |
860 | } | |
861 | top->value = ! v2; | |
862 | top->unsignedp = 0; | |
863 | top->flags |= HAVE_VALUE; | |
864 | break; | |
865 | case '~': | |
866 | if (top->flags & HAVE_VALUE) | |
867 | { | |
868 | cpp_error (pfile, "syntax error"); | |
869 | goto syntax_error; | |
870 | } | |
871 | top->value = ~ v2; | |
872 | top->unsignedp = unsigned2; | |
873 | top->flags |= HAVE_VALUE; | |
874 | break; | |
875 | case '<': COMPARE(<); break; | |
876 | case '>': COMPARE(>); break; | |
877 | case LEQ: COMPARE(<=); break; | |
878 | case GEQ: COMPARE(>=); break; | |
879 | case EQUAL: | |
880 | top->value = (v1 == v2); | |
881 | top->unsignedp = 0; | |
882 | break; | |
883 | case NOTEQUAL: | |
884 | top->value = (v1 != v2); | |
885 | top->unsignedp = 0; | |
886 | break; | |
887 | case LSH: | |
a4a315ef PB |
888 | if (skip_evaluation) |
889 | break; | |
7f2935c7 PB |
890 | top->unsignedp = unsigned1; |
891 | if (v2 < 0 && ! unsigned2) | |
892 | top->value = right_shift (pfile, v1, unsigned1, -v2); | |
893 | else | |
894 | top->value = left_shift (pfile, v1, unsigned1, v2); | |
895 | break; | |
896 | case RSH: | |
a4a315ef PB |
897 | if (skip_evaluation) |
898 | break; | |
7f2935c7 PB |
899 | top->unsignedp = unsigned1; |
900 | if (v2 < 0 && ! unsigned2) | |
901 | top->value = left_shift (pfile, v1, unsigned1, -v2); | |
902 | else | |
903 | top->value = right_shift (pfile, v1, unsigned1, v2); | |
904 | break; | |
905 | #define LOGICAL(OP) \ | |
906 | top->value = v1 OP v2;\ | |
907 | top->unsignedp = unsigned1 || unsigned2; | |
908 | case '&': LOGICAL(&); break; | |
909 | case '^': LOGICAL(^); break; | |
910 | case '|': LOGICAL(|); break; | |
911 | case ANDAND: | |
a4a315ef PB |
912 | top->value = v1 && v2; top->unsignedp = 0; |
913 | if (!v1) skip_evaluation--; | |
914 | break; | |
7f2935c7 | 915 | case OROR: |
a4a315ef PB |
916 | top->value = v1 || v2; top->unsignedp = 0; |
917 | if (v1) skip_evaluation--; | |
918 | break; | |
7f2935c7 PB |
919 | case ',': |
920 | if (CPP_PEDANTIC (pfile)) | |
921 | cpp_pedwarn (pfile, "comma operator in operand of `#if'"); | |
922 | top->value = v2; | |
923 | top->unsignedp = unsigned2; | |
924 | break; | |
925 | case '(': case '?': | |
926 | cpp_error (pfile, "syntax error in #if"); | |
927 | goto syntax_error; | |
928 | case ':': | |
929 | if (top[0].op != '?') | |
930 | { | |
931 | cpp_error (pfile, | |
932 | "syntax error ':' without preceding '?'"); | |
933 | goto syntax_error; | |
934 | } | |
935 | else if (! (top[1].flags & HAVE_VALUE) | |
936 | || !(top[-1].flags & HAVE_VALUE) | |
937 | || !(top[0].flags & HAVE_VALUE)) | |
938 | { | |
939 | cpp_error (pfile, "bad syntax for ?: operator"); | |
940 | goto syntax_error; | |
941 | } | |
942 | else | |
943 | { | |
944 | top--; | |
a4a315ef | 945 | if (top->value) skip_evaluation--; |
7f2935c7 PB |
946 | top->value = top->value ? v1 : v2; |
947 | top->unsignedp = unsigned1 || unsigned2; | |
948 | } | |
949 | break; | |
950 | case ')': | |
951 | if ((top[1].flags & HAVE_VALUE) | |
952 | || ! (top[0].flags & HAVE_VALUE) | |
953 | || top[0].op != '(' | |
954 | || (top[-1].flags & HAVE_VALUE)) | |
955 | { | |
956 | cpp_error (pfile, "mismatched parentheses in #if"); | |
957 | goto syntax_error; | |
958 | } | |
959 | else | |
960 | { | |
961 | top--; | |
962 | top->value = v1; | |
963 | top->unsignedp = unsigned1; | |
964 | top->flags |= HAVE_VALUE; | |
965 | } | |
966 | break; | |
967 | default: | |
ab87f8c8 JL |
968 | cpp_error (pfile, |
969 | (top[1].op >= ' ' && top[1].op <= '~' | |
970 | ? "unimplemented operator '%c'\n" | |
971 | : "unimplemented operator '\\%03o'\n"), | |
972 | top[1].op); | |
7f2935c7 PB |
973 | } |
974 | } | |
975 | if (op.op == 0) | |
976 | { | |
977 | if (top != stack) | |
978 | cpp_error (pfile, "internal error in #if expression"); | |
979 | if (stack != init_stack) | |
980 | free (stack); | |
981 | return top->value; | |
982 | } | |
983 | top++; | |
984 | ||
0f41302f | 985 | /* Check for and handle stack overflow. */ |
7f2935c7 PB |
986 | if (top == limit) |
987 | { | |
988 | struct operation *new_stack; | |
0f41302f | 989 | int old_size = (char *) limit - (char *) stack; |
7f2935c7 PB |
990 | int new_size = 2 * old_size; |
991 | if (stack != init_stack) | |
0f41302f | 992 | new_stack = (struct operation *) xrealloc (stack, new_size); |
7f2935c7 PB |
993 | else |
994 | { | |
0f41302f | 995 | new_stack = (struct operation *) xmalloc (new_size); |
52112c7c | 996 | bcopy ((char *) stack, (char *) new_stack, old_size); |
7f2935c7 PB |
997 | } |
998 | stack = new_stack; | |
0f41302f MS |
999 | top = (struct operation *) ((char *) new_stack + old_size); |
1000 | limit = (struct operation *) ((char *) new_stack + new_size); | |
7f2935c7 PB |
1001 | } |
1002 | ||
1003 | top->flags = flags; | |
1004 | top->rprio = rprio; | |
1005 | top->op = op.op; | |
a4a315ef PB |
1006 | if ((op.op == OROR && top[-1].value) |
1007 | || (op.op == ANDAND && !top[-1].value) | |
1008 | || (op.op == '?' && !top[-1].value)) | |
1009 | { | |
1010 | skip_evaluation++; | |
1011 | } | |
1012 | else if (op.op == ':') | |
1013 | { | |
1014 | if (top[-2].value) /* Was condition true? */ | |
1015 | skip_evaluation++; | |
1016 | else | |
1017 | skip_evaluation--; | |
1018 | } | |
7f2935c7 PB |
1019 | } |
1020 | syntax_error: | |
1021 | if (stack != init_stack) | |
1022 | free (stack); | |
1023 | skip_rest_of_line (pfile); | |
1024 | return 0; | |
1025 | } |